final String value = params.get(fieldName);
        if (StringUtil.isNotBlank(value)) {
            return OptionalThing.of(new Config(value));
        }
        return OptionalThing.empty();
    }

    public static class Config {

        private final String[] values;

        public Config(final String value) {

pkg encoding/json, type UnmarshalTypeError struct, Struct string
pkg expvar, func Handler() http.Handler
pkg expvar, method (*Float) Value() float64
pkg expvar, method (Func) Value() interface{}
pkg expvar, method (*Int) Value() int64
pkg expvar, method (*String) Value() string
pkg go/doc, func IsPredeclared(string) bool
pkg go/types, func Default(Type) Type
pkg go/types, func IdenticalIgnoreTags(Type, Type) bool

  private final String value;

  LegacyComparable(String value) {
    this.value = value;
  }

  @Override
  public int compareTo(Object object) {
    // This method is spec'd to throw CCE if object is of the wrong type
    LegacyComparable that = (LegacyComparable) object;
    return this.value.compareTo(that.value);
  }

  @Override

    public String configParameter;

    @Min(value = 0)
    @Max(value = 2147483647)
    @ValidateTypeFailure
    public Integer depth;

    @Min(value = 0)
    @Max(value = 9223372036854775807L)
    @ValidateTypeFailure
    public Long maxAccessCount;

    @Required
    @Min(value = 1)
    @Max(value = 2147483647)
    @ValidateTypeFailure
    public Integer numOfThread;

        @SuppressWarnings("unchecked")
        K castKey = (K) key;
        V value = getIfPresent(key);
        if (value != null) {
          result.put(castKey, value);
        }
      }
    }
    return ImmutableMap.copyOf(result);
  }

  /** @since 11.0 */
  @Override
  public void put(K key, V value) {
    throw new UnsupportedOperationException();
  }

  /** @since 12.0 */
  @Override

		fallthrough

	default:
		return nil, errNotImplemented
	}
}

func coalesce(args []*Value) (res *Value, err error) {
	for _, arg := range args {
		if arg.IsNull() {
			continue
		}
		return arg, nil
	}
	return FromNull(), nil
}

func nullif(v1, v2 *Value) (res *Value, err error) {
	// Handle Null cases
	if v1.IsNull() || v2.IsNull() {
		return v1, nil
	}

	<Properties>
		<Property name="domain.name" value="${sys:fess.log.name:-fess}" />
		<Property name="log.level" value="${sys:fess.log.level:-info}" />
		<Property name="root.log.level" value="${sys:fess.log.level:-warn}" />
		<Property name="log.pattern" value="%d [%t] %-5p %msg%n" />
		<Property name="log.file.basedir" value="${sys:fess.log.path:-target/logs}" />
		<Property name="backup.date.suffix" value="_%d{yyyyMMdd}" />

	<Properties>
		<Property name="domain.name" value="${sys:fess.log.name:-fess}" />
		<Property name="log.level" value="${sys:fess.log.level:-info}" />
		<Property name="root.log.level" value="${sys:fess.log.level:-warn}" />
		<Property name="log.pattern" value="%d [%t] %-5p %msg%n" />
		<Property name="log.file.basedir" value="${sys:fess.log.path:-target/logs}" />
		<Property name="backup.date.suffix" value="_%d{yyyyMMdd}" />

  public void testPut_supportedPresent() {
    assertEquals("put(present, value) should return the old value", v0(), getMap().put(k0(), v3()));
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPut_supportedNotPresent() {
    assertNull("put(notPresent, value) should return null", put(e3()));
    expectAdded(e3());
  }

        Class<? extends T> type = entry.getKey();
        T value = entry.getValue();
        mapBuilder.put(type, cast(type, value));
      }
      return this;
    }

    private static <T> T cast(Class<T> type, Object value) {
      return Primitives.wrap(type).cast(value);
    }

    /**
     * Returns a new immutable class-to-instance map containing the entries provided to this